* Allow frontmatter typing for .mdx files from glob
`Astro.glob<T>("*.md")` is special cased to allow `T` to be a type for the frontmatter in the markdown. Since .mdx files also get frontmatter added to the globbed result, let's type it as such.
* Add changeset
Co-authored-by: Nate Moore <natemoo-re@users.noreply.github.com>
Co-authored-by: Tony Sullivan <tony.f.sullivan@outlook.com>
